Internet of Vehicles is a vehicle Internet. A mobile communications module is installed on a vehicle terminal, that is, the vehicle terminal has a mobile communication capability, and communication between vehicles can be implemented by using a mobile communications network. Currently, communication modes used for the Internet of Vehicles mainly include two types: a cellular communication mode and a dedicated short range communications (DSRC) technology developed by the United States of America. The cellular communication mode means that an in-vehicle terminal sends a safety message to a base station and the base station processes the safety message. For example, the base station sends the safety message to a traffic information processing server, and the traffic information processing server forwards the safety message to a local area, so as to transmit the safety message to a larger range. The DSRC technology means that a device with a DSRC function is installed on each vehicle, and when a vehicle sends a safety message, a vehicle that receives the safety message may forward the safety message. After being forwarded multiple times by vehicles, the safety message reaches a distance covered by the safety message. For example, when a safety message needs to cover 2000 m and a vehicle on which a device with a DSRC function is installed sends a safety message at a distance of 300 m, the safety message needs to be forwarded six times by other vehicles before reaching a vehicle 2000 m away.
However, in the cellular communication mode, a safety message needs to pass through multiple transmission paths before reaching the traffic information processing server, and then the server determines a transmission area to perform forwarding by using an air interface. Therefore, a long transmission delay problem is caused for the safety message. In addition, in the DSRC technology, when there are few vehicles on a road, for example, there are less than two moving vehicles within 300 m, the safety message cannot be forwarded, that is, the safety message cannot be forwarded to a vehicle in a predetermined distance range; when vehicles on a road are in extremely high density, each vehicle forwards the safety message after receiving the safety message, and therefore, a broadcast storm is caused, and the safety message may not be forwarded to a vehicle in a predetermined distance range within a specified time.